Parkinson’s disease is a chronic (persistent), neurological condition that affects around 120,000 people in the UK.The condition was named after Dr James Parkinson, who first identified it in 1817. Parkinson’s disease affects theway the brain co-ordinates body movements, including walking, talking and writing.Parkinson’s disease affects both sexes, although statistically, men are slightly more likely to develop the conditionthan women. The risk of getting the condition increases with age, with symptoms usually appearing in those whoare over 50 years of age. However, younger people can also be diagnosed with Parkinson’s disease.
Symptoms: The symptoms of Parkinson’s disease usually begin slowly and develop gradually, in no particular order.Parkinson’s disease affects each individual differently and each person with the condition will have a differentcollection of symptoms and respond differently to treatment. The severity of symptoms also differs betweenindividuals with the condition.There are three main symptoms of Parkinson’s disease which are outlined below.
Bradykinesia (slowness of movement): If you have Parkinson’s disease, initiating movement, such as starting to get out of a chair, can become difficult,and it can take you longer to perform tasks. You may also lack co-ordination in your movements. People often putthis slowness of movement down to old age, and many do not have Parkinson’s disease diagnosed until other symptoms occur.
Tremor (shaking): Tremor (shaking) usually begins in one of your hands, or arms. It is more likely to occur when that part of your body is at rest, and usually decreases when you are using it. However, the presence of tremor does notnecessarily mean you have Parkinson’s disease, as it is also a symptom of other conditions, including over-activethyroid (hyperthyroidism), multiple sclerosis, brain inflammation (encephalitis), and alcoholism. Although mostpeople associate Parkinson’s disease with tremor, up to 30% of people with the condition will not have thissymptom.
Stiffness of muscles (rigidity) If you have Parkinson’s disease, your muscles may feel tense and, due to the stiffness, you may have troubleperforming simple, everyday tasks. For example, you may find it difficult to turn around, get out of a chair, and rollover in bed. Making fine finger movements, facial expressions and body language may also become difficult.Other symptoms associated with Parkinson’s disease include:
• constipation and bladder weakness,
• problems with handwriting, speech, and balance, and
• difficulty swallowing.
Causes: Parkinson’s disease is caused by a loss of nerve cells in the part of your brain called the substantia nigra. Thenerve cells are responsible for producing a chemical called dopamine which helps to transmit messages from your brain that control, and co-ordinate, your body movements.If the nerve cells in your brain become damaged, or die, the amount of dopamine is reduced and the messages toyour body become slow and abnormal. When 80% of the nerve cells have been lost, the symptoms of Parkinson’sdisease will appear. Over time, the level of dopamine will continue to fall slowly, and symptoms will becomegradually worse.The reason why nerve cell damage, associated with Parkinson’s disease, occurs is currently unknown. However,two areas that are thought to be responsible are genetics (gene abnormalities) and environmental factors (toxinsand pesticides). These areas are currently being researched in an effort to understand more about the role theyplay in relation to Parkinson’s disease.
Diagnosis:bBased mainly on clinical features. Investigations are required to rule out other causes of symptoms.
Treatment: In the early stages of Parkinson’s disease, you may not need any treatment because the symptoms will usually bemild. However, you may need to have regular appointments with your Neurologist so that the condition can bemonitored. At the moment, there is no cure for Parkinson’s disease, but there are a range of treatments available to helpcontrol your symptoms, and maintain your quality of life. Medication is the main treatment option and there arethree main types that are commonly used – levodopa, dopamine agonist, and monoamine oxidase-B inhibitors.These are described below in greater detail.
Levodopa: Levodopa is a medication that is absorbed by the nerve cells in your brain, and turned into dopamine. It is usuallytaken by mouth, in tablet or liquid form, and is often combined with other medication, such as benserazide, or carbidopa. This prevents the levodopa from being destroyed by enzymes (proteins) in your gut. These medicinesalso reduce the side effects of levodopa, which include nausea, vomiting, tiredness, and dizziness.The first effects of levodopa often show a dramatic improvement in the symptoms of Parkinson’s disease.However, levodopa tends to be less effective over time. This is because as more nerve cells in the brain graduallydie, there are less to absorb the medicine. This means that the dose may need to be increased from time to time.If the dose of levodopa is increased, there is an increased risk of developing side effects. For example, you mayexperience ‘on-off’ effects, where you can suddenly switch between being able to move (on) and being immobile(off). Muscle problems that cause uncontrollable, jerky movements (dyskinesias) is another problem associatedwith long-term levodopa use.
Dopamine agonists: Dopamine agonists have a similar effect to levodopa, but they work in a different way. They lock on to thedopamine receptors in your brain, which receive signals from the dopamine that tell your body to move. Therefore,dopamine agonists act as a substitute for dopamine.
Monoamine oxidase-B inhibitors
Monoamine oxidase-B inhibitors are other drugs for treatment for early Parkinson’s disease. They includeselegiline and rasagiline which work by blocking the effects of a chemical called monoamine oxidase-B in thebrain. This chemical destroys dopamine, so by blocking it, dopamine is able to last longer in the brain. Both of these medicines improve the symptoms of Parkinson’s disease, although their effects are small compared tolevadopa. They can be used alongside levodopa or dopamine agonists.
Surgery: Surgery is sometimes used to treat people who have had Parkinson’s disease for many years. However, surgeryis not suitable for everyone.Chronic deep brain stimulation is a surgical technique that is sometimes used to treat Parkinson’s disease. This iswhere a pulse generator (like a heart pacemaker) is inserted in your chest wall. A fine wire is placed under theskin that attaches to your brain. A tiny electric current is produced from the pulse generator, which runs throughthe wire and stimulates the part of your brain which is affected by Parkinson’s disease. Although surgery does not cure Parkinson’s disease, it does ease the symptoms for many people, particularly if medication is not working well.
Compiled in year 2008. This article is for information only and should not be used for the diagnosis ortreatment of medical conditions. We have used all reasonable care in compiling the information but make nowarranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions.
Dr. Arun K. Dhanuka
MBBS, MD, DM (Neurology)
1799/1, Maharaj Nagar, Near PAU Gate No. 3,Ludhiana (Punjab).Ph: 0161-4662345, 98550-30365, 98147-20265.